Here, the front and rear pitch-setting members provided in the conventional printer described above are formed of metal plates. Thus, the members have good rigidity and can maintain the relative positions of the photosensitive drums with precision. The drawbacks to using metal plates for the front and rear pitch-setting members are the higher material costs and increased weight. Thus, reducing material costs and weight is difficult in a printer provided with such front and rear pitch-setting members.
In view of the foregoing, it is an object of the present invention to provide an image-forming apparatus having a structure that allows for lower material costs and reduced weight while being capable of maintaining the relative positions of photosensitive drums constant.